Lake Fort Scott Bathymetric Survey

1
Lake Fort Scott Bathymetric Survey

• Spring 2006
• Natural Resources and Environmental Sciences
• Kansas State University
• Kevin Bergman
• Kyle Fitzgerald
• Jud Gladin
• Jennifer Hancock
• Tyler Pjesky

Natural Resources and Environmental Sciences
2
Outline

• Introduction
• Purpose
• Background Information
• Bathymetric Survey
• Process and Approach
• Contacts and Resources
• Training
• Conducting Survey
• Analysis
• Assumptions
• Volume Calculations
• Conclusions

3
Purpose

• Develop Map of Lake Bottom
• Estimate Lakes Storage Capacity
• Determine Sedimentation Rate

Lake Fort Scott. www.giskansas.org
4
Background Information

• Lake Fort Scott constructed in 1958 to augment
  water supply
• Original capacity of 2.1 billion gallons or 6485
  acre-feet.
• Water occasionally used from lake during dry
  years to maintain sufficient quality drinking
  water for city.
• Land use within watershed is primarily production
  agriculture (grassland)
• Shoreline property has been sub-divided into 141
  lots for part-time and permanent year round
  residential housing

5
Bathymetric Survey

• Bathymetric Survey A survey of the bottom
  surface of a water body to produce a topographic
  map.
• Uses
• Estimating water volumes
• Mapping bottom surfaces of water bodies for
  exploration

6
Single Beam Echo Sounder

• A single-beam echo sounder produces soundings by
  transmitting short pulses of acoustic energy down
  towards the lakebed and detecting those pulses
  reflected. The depth under the vessel is then
  calculated from the 2-way travel time of pulses
  and the mean speed of sound over the water column

Image taken from pao.cnmoc.navy.mil//
indexunderwater.htm
7
Making Contacts and Acquiring Resources

• Kansas USGSLawrence, KS
• Hypack Inc.Middletown, CT
• Develops software for marine surveys
• Agreed to loan software for one month at no
  charge, 6,500 value
• Odum Hydrographic Systems Inc.Baton Rouge, LA
• Agreed to loan equipment at no charge
• One day of training at no charge, 10,000 -
  15,000 value

8
Training

• Training in Baton Rouge, Louisiana
• Odom Hydrographic Systems Incorporated
• Detailed explanation of the survey process
• Hands-on-training on Mississippi River

Hypack bathymetric survey software
Hydrotrac HT100 single beam echo sounder
9
Conducting Survey

• Equipment Requirements
• Boat
• 2000 Lund 1800 Fisherman
• Power Source
• Generac 5550 Watt/8550 surge generator
• Survey Equipment
• Hydrotrac HT100 single beam echo sounder
• GPS receiver
• Analytical Software
• Hypack
• Laptop
• Dell Inspiron 300m
• Calibration Device
• 8 pound anchor

10
Conducting Survey

• Preparation
• Attach the transducer
• Mount GPS receiver

11
Conducting Survey

• Calibration
• Building a calibrating device

12
Conducting Survey
Dam
NORTH
13
Conducting Survey
Dam Location
Cross Section Lines
Boundary Line
14
Analysis

• Assumptions
• Volume Calculations
• Hypack
• Notepad
• Microsoft Excel
• AutoCAD Land Desktop
• Map and Volume

15
Assumptions

• Minimum depth 2
• Lake perimeter adjusted
• Lake aerial image
• Lake floor

16
Volume Calculations

• Hypack
• Notepad
• Microsoft Excel
• AutoCAD Land Desktop

2393474.48 1736804.91 840.30 2393543.38
1736881.02 843.00 2393618.11 1736951.12
841.60 2393700.28 1737010.30 839.70 2393787.47
1737060.83 837.40
1 2392920.09 1742689.33 844.9 2
2392940.53 1742683.83 843.2 3
2392960.56 1742682.78 842.1 4
2392981.52 1742685.28 841
17
Results

• 1957 2006
• 6,485 acre feet 5,980 acre
  feet
• 505 acre feet of sedimentation
• 7.8 capacity loss
• 10.31 acre feet per year
• 0.16 capacity loss per year

18
Conclusions

• The sedimentation rate of the lake may not be the
  major concern with quality water supply to the
  city.
• Adjacent land use may require better regulation.
• Rate is based on two points of data over 50 years
  apart which does not give an accurate indication
  of lake conditions.

19
Alternative Surveying Techniques

• Hardware Alternatives
• Multi-beam Echo-sounder
• Fishfinder/Depth finder
• Manual depth recordings

• Software Alternatives
• Hypack (for analysis and modeling)
• Trimble HYDROproTM

20
Service Learning Goals

• Contribution to Community
• Professional Development

21
Cost Comparison

• Project budget 2000
• Project expenses 1500
• Software donated by Hypack Inc (actual cost
  6500)
• Equipment donated by OHSI (actual rental cost
  95/day shipping, etc)
• Training donated by OHSI (actual cost 800/day)
• Personnel hours donated (actual consulting cost
  150/hr)
• Cost to hire a professional consultant to perform
  a similar survey approximately 20,000
• Cost to City of Fort Scott
• 2 nights at Best Western
• Learning Experience Priceless

22
Acknowledgments

• City of Fort Scott
• Kansas Department of Health and Environment
• WaterLINK
• Odom Hydrographic Systems Inc.
• Hypack Inc.

Questions?